In U.S. Pat. No. 3,643,851, assigned to the present assignee and entitled SKIN STAPLER, there is disclosed a surgical stapler for joining the disunited skin of a patient. The surgical stapler disclosed in this commonly assigned patent employs a staple-carrying cartridge comprising an anvil adapted to lie flush with the skin, a plurality of staples which are to be folded around the anvil, and a pusher for ejecting and bending the staples around the anvil. The surgical stapling instrument adapted to accept the staple-carrying cartridge in this commonly assigned patent is powered by a pressurized gas. Later developments of the gas-powered stapler and cartridges for applying surgical staples to external skin and internal fascia are disclosed in U.S. Pat. No. 3,662,939, assigned to the present assignee and entitled SURGICAL STAPLER FOR SKIN AND FASCIA.
Although these gas-powered instruments represent a marked advance over the state-of-the-art, there are certain disadvantages associated with the use of gas-powered units of this type. One of the obvious disadvantages is the necessity for replacing the gas cartridges after their contents have been exhausted, and a second is the inconvenience associated with storing and maintaining a supply of these cartridges. Also, the powering mechanism is complex, is hence somewhat costly, and comprises numerous close-tolerance elements which tend to be susceptible to malfunction. For these and other obvious reasons, it would be advantageous to have a simple surgical stapling instrument adapted to accept staple-carrying cartridges, but which is powered manually and without the intervention of a gaseous medium and the disadvantages associated therewith.
A manually powered surgical stapling instrument adapted to accept staple-carrying cartridges of the type disclosed in the above commonly assigned patents is disclosed in U.S. Pat. No. 3,819,100, assigned to the present assignee and entitled SURGICAL STAPLING INSTRUMENT. The surgical stapling instrument generally comprises a pusher-activating means for driving the pusher element of the staple-carrying cartridge to eject and form the staples around the anvil means of the cartridge including a thrust bar slidably mounted for reciprocative movement in the nose portion of the stapler. The surgical stapling instrument also comprises drive means to activiate the staple-advancing means in the staple-carrying cartridge for driving the staples toward the anvil including pinion gears and pinion shafts also housed within the nose portion of the stapler.
Recently, cartridges have been designed which eliminate the requirement for the complex gearing once needed in the powering of the instrument. With these cartridges, the output shaft of the powering instrument need only have rectilinear thrust capabilities. The staples are advanced by means designed into the cartridges themselves. In commonly assigned U.S. Pat. No. 3,618,842 entitled SURGICAL STAPLING CARTRIDGE WITH CYLINDRICAL DRIVING CAMS, the advancing pusher, integral with the cartridge, rotates a pair of staple-driving screws by means of cams formed in the rear portions of the screws. In commonly assigned U.S. Pat. No. 3,638,847 entitled RACHET DRIVEN CARTRIDGE FOR SURGICAL INSTRUMENTS, the staples are driven forward by the interaction of pairs of opposing ratchet teeth integral with the cartridge. Finally, in commonly assigned U.S. Pat. No. 3,717,294 entitled CARTRIDGE AND POWERING INSTRUMENT FOR STAPLING SKIN AND FASCIA, a flexible toothed belt is moveably housed in a main body. Staples are guided and advanced by association with spaced teeth of the flexible belt. The cartridge is equipped with an anvil integral with the main body and a pusher which serves the functions of advancing the staples and singly ejecting and forming the same.
Accordingly, it is a broad object of the present invention to provide a surgical stapling instrument for stapling the disunited skin or fascia of a patient which is manually powered and wholly operated by mechanical means.
It is another object of the present invention to provide a surgical stapling instrument which is adapted to associate with a cartridge requiring only rectilinear thrust capability.
It is still another object of the present invention to provide a surgical stapling instrument which is uniform and smooth to operate and which consistently forms the staples with the same mechanical force.
It is yet another object of the present invention to provide a surgical stapler in which the staple-carrying cartridge is mounted so that it is rotatable relative to the hand-held main body portion of the instrument so that the staples can be applied at any angle without the necessity for rotating the hand-held portion of the instrument.
Another object of the present invention is to provide a surgical stapler with means for ensuring that the staple-advancing drive means of the instrument is activated only once in each stapling operation.
These and other objects of the invention, as well as many of the attendant advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.